Fan device capable of increasing air pressure and air supply

ABSTRACT

A fan device capable of increasing air pressure and air supply includes a fan frame, a base and a fan wheel. The fan frame has an air inlet side, an air outlet and a flow path which defined by the inner wall of the frame. The base is disposed in the flow path and joined to the inner wall of the fan frame by means of a plurality of elongated fan blade shaped connecting parts being attached to the inner wall of the frame. The fan wheel is movably attached to the base from the air inlet side. The base further includes a main base part and a shoulder part with a streamline contour extending from a lateral side of the main base part to approach the air outlet side of the fan frame such that a concave inward curved surface converging toward a central axis of the base is formed with a tip end is disposed at the central axis to concentrate fluid flow and increase air pressure for eliminating stagnation zone and promoting heat dissipation.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to a fan device and particularly to a fan device capable of increasing air pressure and air supply for eliminating stagnation zone behind the base of the fan device.

2. Brief Description of the Related Art

Normally, the conventional fan includes a fan wheel and a fan frame. The fan frame has a base for being rotatably attached with the fan wheel, an air inlet and an outlet. The air outlet is disposed corresponding to a heat generating component and the fan frame is attached to the heat generating component with at least a fastening element. Due to the base having a flat shape area, a low pressure zone is constituted behind the base. When air flows outward the fan frame via the outlet, air flows back at the low pressure zone instead of moving to the heat generating component to decrease heat dissipation efficiency tremendously.

In order to overcome the preceding deficiency, Taiwan Patent Application Publication No. 200622111 entitled “GUIDE FLOW DEVICE FOR A FAN” provides a flow guide device at the outlet side corresponding to the a heat sink. The flow guide device includes a guide flow shield and a guide element disposed in the guide flow shield. The guide flow shield has a shape of nozzle with a streamline curved surface at the inner side thereof. The end with a large diameter is the air intake port and the end with small diameter is the air outward port. The guide element is disposed at the air intake port corresponding to the hub and has a shape of convergence with a streamline outer surface.

When the fan is started to produce forcing air flow, the air flow enters the guide flow device via the air intake port and passes through the guide flow shield and the guide element. Then, the air flow moves outward via the air outward port and becomes high speed uniform shooting flow.

However, a problem of the preceding prior art is in that the air outward port of the guide flow device has a fixed area to limit amount of air flow such that only a certain area of the heat sink can perform heat exchange with the air flow. Another problem of the preceding prior art is that the fan and the flow guide device vibrate during the fluid flowing to the guide flow device to increase noise. Moreover, a further problem of the preceding prior art is that the guide flow device increases costs and weight of the fan.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a fan device capable of increasing air pressure and air supply in which the base has a main base part with a concave inward curved surface being convergent along with extending toward the air outlet side for guiding the fluid to a heat sink under the base.

another object of the present invention is to provide a fan device capable of increasing air pressure and air supply in which the concave inward curved surface is capable of gathering the air flow and increasing air pressure for decreasing noise.

In order to achieve the preceding object, a fan device capable of increasing air pressure and air supply according to the present invention includes a fan frame, a base and a fan wheel. The fan frame has an air inlet side, an air outlet and a flow path which defined by the inner wall of the frame. The base is disposed in the flow path and joined to the inner wall of the fan frame by means of a plurality of elongated fan blade shaped connecting parts being attached to the inner wall of the frame. The fan wheel is movably attached to the base from the air inlet side. The base further includes a main base part and a shoulder part with a streamline contour extending from a lateral side of the main base part to approach the air outlet side of the fan frame such that a concave inward curved surface converging toward a central axis of the base is formed with a tip end is disposed at the central axis to concentrate fluid flow and increase air pressure for eliminating stagnation zone and promoting heat dissipation.

BRIEF DESCRIPTION OF THE DRAWINGS

The detail structure, the applied principle, the function and the effectiveness of the present invention can be more fully understood with reference to the following description and accompanying drawings, in which:

FIG. 1 is a perspective view illustrating a fan wheel being detached from a fan frame of a fan device according to the present invention;

FIG. 2 is a bottom view of a fan device according to the present invention;

FIG. 3 is a plan view of a base of a fan device according to the present invention;

FIG. 4 is a sectional view of a fan device according to the present invention; and

FIG. 5 is a sectional view of the fan device according to the present invention joined to a heat sink illustrating how fluid flows through the fan.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1, to 3, a fan device according to the present invention includes a fan frame 11 and a fan wheel 12. The fan frame 11 has an outlet side 111, an inlet side 112 and a flow path 113 communicating the inlet side 111 and the outlet side 112. Further, a base 13 is disposed in the flow path 113. The base 13 includes a main base part 131 and a shoulder part 132. It can be seen in FIG. 3, The shoulder part 132 has a streamline contour extending from a lateral side of the main base part 131 to the inlet side 111 of the fan frame 11 and provides a concave inward curved surface 133 converging toward the central axis 14 such that a tip end 134 is formed at the central axis 14.

Referring to FIG. 2 again, the base 13 is joined to the inner wall of the fan frame 11 with a plurality of elongated fan blade shaped connecting parts 15 such that the base 13 is held in the flow path 113.

Referring to FIG. 4, the fan wheel 12 is rotatably to the base main part 131 opposite to the curved surface 133 and the tip end 134 of the curved surface 133 does not exceed the outlet side 111 of the fan frame 11. That is, the tip end 134 extends to the outlet side 111 or to a position having a distance from the outlet side 111.

Referring to FIGS. 1, 2 and 4 again, the inner wall of the fan frame 11 further is attached with a plurality of fan blade shaped guide parts 16 opposite to base 13 laterally and each of the guide parts 16 has a joining side 161 being attached to the inner wall of the fan frame 11 with a free side 162 facing the base 13. Thus, a first space 171 is formed between the free side 162 and the circumferential side of the base 13 and a second space 172 is formed between adjacent guide parts 16 respectively.

Referring to FIG. 5 in company with FIG. 4 again, the fan frame 11 is assembled to a heat sink 18 in a way of tip end 134 of the base 13 being disposed next to the heat sink 18. When the fan wheel 12 rotates, fluid moves toward the heat sink 18 from the inlet side 112 of the fan frame 11. The fluid, which passes through the first space 171 and the second space 172, is directed by the guide parts 16 to gather at the base 13 and smoothly move along the curved surface 133 to the heat sink 17 so as to eliminate fluid stagnation zone behind the base 13. Hence, deficiency concerning the fluid being hindered by the base to result in the fluid being incapable of reaching the heat sink to conduct heat exchange can be overcome for enhancing effect of heat dissipation. Furthermore, the fan device of the present invention is capable of concentrate the fluid without flowing outward the fan frame 11 immediately for increasing air pressure.

In addition, the fluid moving along the curved surface 133 of the base 13 is capable of lessening back flow to decrease noise created by the fluid.

It is noted that although the fan device of the present invention has arrange the guide parts at the inner wall of the fan frame, function of concentrating the fluid at the base can be performed as well even if no guide parts are provided.

While the invention has been described with referencing to a preferred embodiment thereof, it is to be understood that modifications or variations may be easily made without departing from the spirit of this invention, which is defined by the appended claims. 

1. A fan device capable of increasing air pressure and air supply comprising: a fan frame with an circumferential inner wall, having an air inlet side, an air outlet and a flow path, and the flow path being defined by the inner wall and communicating with the air inlet side and the air outlet side; a base, being disposed in the flow path and joined to the inner wall of the fan frame by means of a plurality of elongated fan blade shaped connecting parts attached to the inner wall of the fan frame; and a fan wheel, being movably attached to the base from the air inlet side; wherein the base further comprises a main base part and a shoulder part, which has a streamline contour extending from a lateral side of the main base part to approach the air outlet side of the fan frame, and provides a concave inward curved surface converging toward a central axis of the base such that a tip end is formed at the central axis.
 2. The fan device capable of increasing air pressure and air supply as defined in claim 1, wherein the fan wheel is disposed at another side of the base opposite to the top end.
 3. The fan device capable of increasing air pressure and air supply as defined in claim 1, wherein a plurality of fan blade shaped guide parts surrounding the base and each of the guide parts has a joining end side being attached to the inner wall of the fan frame and a free end side being opposite to the joining end side and facing the base such that a first space is formed between the base and the free end side.
 4. The fan device capable of increasing air pressure and air supply as defined in claim 3, wherein a second space is formed between every two adjacent guide parts.
 5. The fan device capable of increasing air pressure and air supply as defined in claim 1, wherein the tip end is disposed at a position next to the outlet side. 